My criteria was that they either deserve it by the way they raced (Bettini, Kwiatkowski, Pedersen), or they were the outright favourite (Cipollini, Cavendish).So Pedersen belongs in your list only because he went in the break? He doesn't meet any of the other criteria you mentioned. Not a favourite, wasn't even mentioned. Only thing he really archieved before that was a second place in Flandres.
Boonen on the other hand was one of the favourites after having won E3, Flandres, Roubaix, 2 stages in the Tour and a ton of other victories. You might as well leave the other sprinters out of your list as well if the reason you left him out is because "his main effort was following".
Already having a good track record is a bonus (because I think WC should have shown already they are able to win a variety of big races, best example isValverde), but even in that case they still have to earn it by the way they race or being a favourite.
Pedersen wasn't a favourite but he was a very worthy winner, solely on the basis of how he helped to shape up the race.
To give a counter example: Hushovd won the WC in 2010 simply because the big favourite (Gilbert) went too early, not because Hushovd made the race / was best in the race / was the top favourite. Same with Rui Costa, and even with Evans in 2009: Cancellara made that race from beginning to end, and only lost because everybody was racing against him, not because Evans was stronger than the others in that lead group. So those wins involve more luck than outright the strongest.
In Imola 2020, Alaphilippe won because he was much stronger than anybody else and once he attacked he rode a very brave ride, and if he wasn't caught by the chase group, it wasn't becasue that chase group let him take the win. They really dug deep to catch him, but they couldn't. So for me, a very worthy winner.